Among secondary batteries mounted on a vehicle such as a plug-in hybrid car, a secondary battery capable of performing normal charging in which charging is performed through an in-vehicle charger from an AC power source of 100 V and performing fast charging in which charging is performed through a ground non-portable charger from an AC power source of 200 V may be used.
PTL 1 discloses a technique that provides various charging methods according to situations when both of a fast charging plug and a normal charging plug are connected to a vehicle in charging of a secondary battery.